An aquifer is a layer of rock or sand that holds an underground lake.
Water comes up to the surface through springs, and is often pumped for
drinking water. The Edward's Aquifer is made up of a layer of limestone with
a bunch of holes and caves, sort of like swiss cheese rock, with water running
all through it. The holey-rock is called Karst.

How big is the Edward's Aquifer?

The Edwards Aquifer is under Central Texas and runs along the Balcones
Escarpment between Austin and Uvalde. It's 160 miles long (measuring from
Brackettville to Kyle) and can be from 5 to 40 miles wide. It's under
Uvalde, Medina, Bexar, Comal and Hays counties.

What's so important about the Edward's Aquifer?

The Edwards Aquifer supplies drinking water for 1.5 million people,
including San Antonio up through Austin. The aquifer provdies water for farms,
agriculture and industry of the region. Water from the Comal and San Marcos
Springs provide water for recreation like water parks, habitat for several
endangered species endangeredspecies.phtmll, and water that flows downstream
to the Gulf Coastal Plain, and the San Antonio Bay ecosystem.

Is a widemouth blindcat a cat?

The widemouth blindcat is a rare fish found in underground waters. In Texas,
it's been spotted in the Edwards Aquifer about 1,350 and 2,000 feet underground!
They don't have eyes or eye sockets. The fish is without pigment (color) or an air
bladder (Most fish have an air bladder. They adjust their air bladder, which is
sort of like a tiny balloon inside of them, to go to the top or the bottom of the
water, and use their fins to steer). A blindcat will eat about anything it can catch.
The maximum length known is approximately 5.5 inches. This fish is threatened by
overpumping of the aquifer in the area where it is found. In addition, drawdown
of the aquifer in the area threatens to allow the intrusion of poor quality water
into the habitat of the fish.

What else lives in the Edward's Aquifer?

The widemouth blindcat and its relative, the toothless blindcat, share the
aqifer with about forty species of macroinvertebrates (bugs).